Fuel burning device



Patented July 12, 1.932.

PIATENr. OFFICE GARNET W. Maxim, or nocKFoRD; ILLINOIS l FUEL BURNINGDEVICE j naces. Various precautions have been resorted to, such as usingnozzles or tubes composed of refractory material of a high ygrade orcovered in part by such material. In other instances, the mixing tube ornozzle of the burner has' been partially concealed in the furnace wallto protect it from reiected heat. But in most instances, whatever theconstruction was, all of these burners when used with high pressure gasor air in high temperature furnaces were either unable to keep the pro,

jected mixture burning as the flame was easily blown so far off the endof 'the nozzle that ignition of the mixture failed or the burner shortlyburned itself out.v My invention includes a mixing tube for use with afue'l mixer which is satisfactorily protected from high furnacetemperatures and which also is constructed so as to decrease materiallythe likelihood of the flame being extinguished `when the mixture isprojected at high velocity.

y One of the objects of this invention is to provide a mixing tube forconducting combustible mixtures into furnaces which' is adapted to aidin the maintenance of combustion.

Another object of this invention is to provide'a fuel burning device inwhich a mixing tube is so disposed in a furnace wall as to protect thetube from destruction by heat and yet promote and secure efficient andcontinuous combustion of the mixture projected from the tube.

Another object of this invention is to provide a fuel burning device inwhich a mixing tube is disposed in a furnace Wall in such a manner as toprotect it from radiated heat 'tion and Will-later appear.

Application iled May 14,-1927` Serial No. 191,326.

and to cause the mixture projected from it to absorb heat from the wallsof the tube.

Further objects, advantages and capabilities are inherently possessed bythis inven- Referring now to t e drawing, the figure discloses a mixergenerally indicated as 11 into which is conducted-high pressure gasthrough a pipe 12, the flowv of lgas being regulated by the valve 13. Amovable shutter 14 60 regulates the admission of air in a mannerWell-known in this art. The high pressure gas is projected through theorifice 15 and entrains upon itself air which is drawn in past theshutter 14. l j

The mixer is secured to a fuel delivery tube 16 by means, of the threads17 and the inner end 18 of the tube extends into a passageway 19 in thefurnace wall. In order that the tube maybe rigidly securedin position,it is connected in a suitable ymanner to the plate 21, which plate isfastened to the Wall of the furnace. The inner extremity of themixingtube is chamfered as at 22. The passageway in the furnace Wallthen slightly expands. as in the portion 23 and eventually terminates atthe interior wall 24 of the combustion chamber. As will be obvious toone skilled in this art this fuel burning device is applicable to manytypes so of furnaces and it will therefore be understood that thefragmentary portion of a combustion chamberwall 24 shown in the drawingmay be a part of any one of many types of furnaces into which gaseousfuel mixtures are projected. An example of such al combustion chamberwould be the ordinary rectangular chamber of a furnace lfor annealingsmall forgings. j

When a mixture is being proj ectedat high velocity through the mixingtube, it expands when passing through the expanding portion 18 of thetube and asit leaves the chamfered extremity 22, part of the mixturerolls off that edge in eddy currents which proceed to roll along theexpanding portion 23 of the passageway in the fire brick Wall 25.Consequently, the velocity in a longitudinal direction of the gas movingin these eddy currents `will be considerably less than the velocity of10l u less than the diameter of the part of the pass lthe flame will begreater than the general i 'longitudinal motion of the eddy currents andwill enable the flame to maintain itself in these eddy currents eventhough it might have a tendency to be blown oil' from the centralportion of the projected stream of mixture. The flame thus maintained inthe eddy currents will maintain the ignition of the entire mixture andwill avoid the serious consequences which sometimes result from theblowing out of the flame without shutting oi the mixer.

Not only does this appara-tus provide a means for maintainingcombustionunder abnormal conditions, but it also protects the mixing tube fromexcessive temperature by disposing the extremity of the tube well back yfrom the combustion chamber within the lire sive heat.

brick wall. With this device, it is not necessary to maintain anextremely hightemperature near the end of the burner in order to obtaincombustion because of the novel construction whichresides in thechamfered edge of the tube. One is enabled to keep the extremity of themixingtube well backv from the combustion chamber to protect it fromexces- By reason of the expanding taper of the tube near its extremitythe mixture expands as it makes its exit'from the tube and picks up heatfrom the tube walls, thus reducing the temperature of the tube andprolonging its life. This is a valuable feature since it is inevitablethat some heat will be conducted through the fire brick directly to thetube.

By means of the disclosed construction,

' an apparatus is provided which is well adapted to maintain combustionunder normal and abnormal conditions and which is' so arranged as topromote the long life and eicient serviceabilit of the device.

It should be un erstood that the illustrated..

embodiment of the invention may be modified considerably withoutdeparting from the spirit and scope of the invention.

Having shown and described my invention,

I claim:

' 1. In combination with a combustion chamsage through which themixture. flows after leaving the tube.

2. In combination with a combustion chamber wall having a passagetherethrough a fuel delivery tube extending into and terminating in saidvpassa-ge, means for projecting a stream of combustible mixture throughsaid tube and said passage, the posterior part of the tube having ataper expanding toward its extremity, said extremity having a.cha-mfered edge for causing eddying currents of the mixture to roll moreslowly along the posterior surface of the passage than the main body ofthe stream flows through the central portion of the passage. v

3. In combination with a Wall having a passagey therein, a fuel deliverytube extending into and terminating within said passage, and means forprojecting a combustible rmixture through said tube, the extremity ofthe tube within the passage being chamfered toward the adjacent passa ewall to cause nart of the mixture issuing om the tube to roll oil' theend of the tube along the wall of the passa-ge in eddy currents, thepassage immediately beyond lthe .end of said ltube being free ofobstructions such as-might disrupt rearward propagation of flame throughsaid eddy currents.

4. In combination with a combustion chamber wall having a passagetherethrough, a Itube projecting into and terminating in the passage fordelivering a fuel mixture into the chamber and having a chamfered openend curved toward the passage Wall constructed and arranged for causingpart of the mixture delivered from the tube to roll along the surface ofthe passage in eddying currents having a general longitudinal motionslower than the velocity 'of the main stream and maintaining intimate'contact with the mainstream alongth'e chamfered surface of said end,the passage being free frgm obstructions beyond the end of the tu e.

In witness of the foregoing I aiix my signature. l

GARNET W. MCKEE.

fuel delivery tube extending into andterminating within said passage,-means for projecting a combustible mixture through said tube, theextremity of thev tube having a -chamfered edge for producing eddycurrents in the mixture 'along the wall of said passage, the internaldiameter of the tube near its chamfered extremity being considerably

